1. Field of the Invention
The present invention relates generally to a hammer head for striking a string in an acoustic piano, and more particularly to a moisture-proof hammer head for a piano and a method of manufacturing same.
2. Description of the Related Art
As is well known in the art, a hammer head for an acoustic piano is composed of a shaft-like hammer wood made of a solid woody material and a hammer felt made of wool felt and adhered around a front end portion of the hammer wood. The hammer head is rotatably mounted at a location above and behind an associated key, and is driven to rotate by an action in response to a depression of the associated key such that a front end portion of the hammer felt strikes a string stretched therebehind to cause vibration of the string, thus generating acoustic piano sound. In addition, for providing satisfactory piano sound characteristics in accordance with particular sound ranges, the hardness of the hammer felt is set lower toward the lower sound side and higher toward the higher sound side.
In the hammer head as mentioned above, the hammer felt is highly susceptible to absorbing moisture (humidity), and the hammer felt, when absorbing moisture, exhibits a lower hardness, thus failing to provide a predetermined piano sound characteristic. For example, a damped hammer felt will reduce dilatation of piano sound. Thus, as a hammer head for preventing such an inconvenience, there is conventionally known a hammer head having a resin impregnated in a half portion of a hammer felt on the base end side (near a hammer wood). The impregnated resin provides a moisture-proof capability for the hammer felt. In addition, a plurality of hammer heads are wrapped together with a vinyl sheet or the like for the same purpose when a piano is shipped.
The prior art technique for impregnating a resin into a hammer felt for preventing the hammer felt from absorbing moisture, however, implies several problems. For example, the resin itself causes a high material cost. Also, a manufacturing period becomes longer because subsequent steps must be pending until the impregnated resin is dried, so that a manufacturing cost of the hammer head is increased. While the method of wrapping hammer heads with a vinyl sheet or the like upon shipping in turn is simple and inexpensive, its humidity preventive effect is limited only from shipment to arrival of a piano at a client, and is not available after the client begins to use the piano.